In a so-called “hybrid vehicle” provided with an electrically driven motor for driving a vehicle separately from an engine, in some cases, a battery (electric power source) for the electrically driven motor is mounted in a trunk room of the vehicle as disclosed for example, in Japanese Patent Application Laid-open (JP-A) No. 2005-88752. Moreover, in the above document, a construction is disclosed that a cooling duct is disposed in a rear parcel part for separating a vehicle compartment from the trunk room. The cooling duct has its one end opened in the interior of the vehicle compartment and has its other end connected to the trunk room. Air sucked from one end of the cooling duct (interior of the vehicle compartment) by a cooling fan passes through the cooling duct and is supplied into the trunk room, and the battery is cooled by the air supplied into the trunk room.